1. Field of the Invention
The present invention relates to a display panel and an image display apparatus.
2. Description of the Related Art
Image display apparatuses such as a field emission display (FED) are known that are of a type in which electrons emitted from electron-emitting devices are radiated onto a light emitter such as a phosphor. Such image display apparatuses use a display panel provided with a flat, rectangular vacuum vessel in which the interior thereof is maintained at a pressure lower than atmospheric pressure (vacuum). In order to maintain the internal space in a vacuum, a plurality of spacers are typically provided within the flat, rectangular vacuum vessel
In an image display apparatus having a display panel provided with a flat, rectangular vacuum vessel in this manner, it is required to prevent the vacuum vessel from being damaged by impact to the image display apparatus. In addition, it is also required to not only prevent damage to the exterior of the vacuum vessel, but also to prevent damage to members relating to the image display located within the vacuum vessel. Examples of impact that cause damage to the vacuum vessel include impact to the image display apparatus from the outside, impact occurring during transport or installation, and impact caused by dropping due to careless handling.
Japanese Patent Application Laid-open No. 2005-011764 discloses a reinforcement frame attached to the back (side on the opposite side from the display side) of a vacuum vessel that composes a display panel in order to improve the mechanical strength of the vacuum vessel. The reinforcement frame is disclosed to have a pair of first frame sections extending nearly parallel to the long side of a flat, rectangular vacuum vessel, and a pair of second frame sections extending nearly parallel to the short side of the vacuum vessel and coupled to the pair of first frame sections.
Japanese Patent Application Laid-open No. 2006-185723 discloses a vacuum vessel provided with long, narrow plate-like spacers arranged so that each of the lengthwise directions thereof are parallel. A mode is disclosed therein in which long, narrow plate-like spacers are contacted in a plurality of spacer contact layers intermittently provided on a metal back layer that covers a light-emitting surface. In addition, Japanese Patent Application Laid-open No. H10-326580 discloses the providing of a protective plate on a display surface of a vacuum vessel that composes a display panel.
It was conventionally necessary to increase the strength of vacuum vessels by providing a high-strength back supporting member in the manner of the reinforcement frame disclosed in Japanese Patent Application Laid-open No. 2005-011764 on the back of a vacuum vessel that composes a display panel. More specifically, in order to obtain adequate strength, the impact resistance (reinforcement strength) of the vacuum vessel was increased by increasing the thickness of the back supporting member. Consequently, this resulted in problems such as increased weight and cost of the image display apparatus. In addition, the presence of a large back supporting member limited the area in which a power supply and printed circuit boards such as a drive circuit could be mounted, thereby resulting in problems such as having an effect on the capacity to reduce the thickness of the image display apparatus.